Table 3.

Mean Hounsfield units (HU) inside the lung for the deep inspiration breath hold (DIBH) state, or HU _DIBH , and for the end of exhalation (EE) state, or HU _EE , and the absolute difference between them, followed by the HU difference (mean ± standard deviation) of deformable image registration both before and after density correction

Patient no.	HU DIBH	HU EE	$\left|H{U}_{\mathit{DIBH}}-H{U}_{\mathit{EE}}\right|$	HU difference before density correction	HU difference after density correction
1	−817	−702.5	114.5	58.9 ± 48.3	17.7 ± 34.7
2	−827.3	−671.1	156.2	63.7 ± 48.1	16.2 ± 34.1
3	−804	−627.1	176.9	67.9 ± 42.2	12 ± 28.6
4	−834.7	−765.6	69.1	49.3 ± 52.1	22.6 ± 40.8
5	−831.5	−735.4	96.1	60.7 ± 42.6	21 ± 37.2
6	−835.5	−711.8	123.7	65.0 ± 56.8	24.1 ± 42.6
7	−791.7	−702.4	89.3	51.4 ± 44.8	16.4 ± 32.5
8	−840	−796.4	43.6	33.8 ± 39.6	20.8 ± 37.2
9	−825.4	−780.4	45	39.4 ± 40.3	19.6 ± 34.5
10	−708.4	−611.4	97	50.5 ± 41.6	15.7 ± 31.7
11	−818.6	−726.5	92.1	50.0 ± 54.7	23.4 ± 42.5
12	−716	−588.5	127.5	46.3 ± 34.6	9.8 ± 23.2
13	−875.3	−773.8	101.5	66.6 ± 45.5	18.4 ± 36.1
14	−850.7	−741.2	109.5	59.7 ± 45.8	15.9 ± 33.5
Mean	−812.6	−709.6	103	54.5 ± 45.5	18.1 ± 34.9